In medical devices for extracorporeal blood treatment (dialysis) frequently tube roller pumps are employed for returning the blood withdrawn from the patient to a dialyser and back to the patient. Such tube roller pumps are peristaltic pumps, wherein a loop-shaped tubing segment is adjacent to an appropriately bent bearing surface of the pump housing. A rotor of the pump located inside the bearing surface then moves with its outer edges along the tubing segment, wherein the tube is locally indented and thus the elastic material properties of the tubing segment enable blood to be fed through the tubing segment. For this, the blood is fed to the tubing segment via a first port and is discharged via another port at the other end of the tubing segment. In this way, together with the feeding and discharging lines and several air traps, for instance, the tubing segment forms a transfer system, as it is called, by which the blood of the patient is fed to a dialyser and back to the patient.
Those transfer systems are preferably exchanged after each treatment and are not re-used for other patients. A used tubing segment thus need not be removed from the pump before a new transfer system is introduced to the device. In order to facilitate handling during removing and mounting the transfer system it is known to provide a connector adapted to be connected to a feeding and discharging line at each of the two ends of the tubing segment. However, such connectors are merely connecting pieces and fulfill no further functions. It is a drawback of such manual systems that confusions may occur upon insertion into the pump. This problem can be solved, for example, by color encoding and/or geometrical encoding.
Furthermore, multi-connectors are known which unify both ports for feeding and discharging lines in one component part which is then adapted to be introduced into a receiving portion of the pump housing. Due to their geometrical shape and their material properties those components frequently permit simple and unambiguous insertion of the pump segment into the pump. A geometrical encoding excludes any incorrect mounting position. However, those systems frequently lack an operating surface for inserting the system into the pump which impedes manipulation.
Moreover automatic systems intended to take over and thus facilitate threading and unthreading are known. Frequently for unthreading an actuator has to be actuated which moves the system from its therapy position into an unthreading position via a linear drive, for example. For this purpose, it may be required in such systems to operate a switch/button on the medical device or to touch a software button on a user interface.